Chemistry

Question 1

Group 7 properties
Reactivity
Melting point
Boiling point 
Electronegativity

Answer 1

Less reactive
High melting point
Higher boiling point
Electronegativity decreases (astract pair of electrons)

Question 2

Halogen order and colours

Answer 2

Fluorine - yellow gas
Chlorine - dense green gas
Bromine- red/brown volatile liquid
Iodine- dark grey crystalline solid or purple vapour

Question 3

What happens when more reactive halogen reacts with a less reactive halogen salt?

Answer 3

Ir displaces it

Higher up group displaces

Question 4

What is volatility?

Answer 4

How easily a liquid evaporates

Question 5

What is a mixture?

Answer 5

When a solid(solute) and a liquid (solvent) are added together and bonds between solvent break and solute mixes with liquid =solution

Question 6

What is a solution?

Answer 6

A mixture of solute and solvent that does not separate out

Question 7

What is a solute?

Answer 7

Substance being dissolved

Question 8

What is the solvent?

Answer 8

The liquid it’s dissolveing into

Question 9

What is soluble?

Answer 9

Means it will dissolve

Question 10

What is the solubility?

Answer 10

How much it will dissolve

Question 11

Nail varnish solubility in water?

Answer 11

Insoluble, attraction between nail varnish molecules is stronger than that between it and water and vice versa

Question 12

Nail varnish in acetone?

Answer 12

Soluble (nail varnish remover) stronger atteactoon between nail varnish and acetone

Question 13

How can you remove a metal from an ore?

Answer 13

Reduction by carbon (if less reactive)

Electrolysis

Displacement (other metal is more reactive)

Question 14

What is electrophillic addition?

Answer 14

Double bond is attacked by electrophiles (positive ions or polar molecules)

Question 15

Conditions for polymerisation?

Answer 15

Pressure

Catalyst

Temp and pressure effect polymer formed

Question 16

What is non biodegradable?

Answer 16

Won’t rot

Question 17

Alcohols react with sodium?

Answer 17

To give alkoxides

Question 18

Uses of alcohols?

Answer 18

In cells to dissolve fats etc

Perfume

Clean paint brushes

Fuel

Question 19

Carboxylic acid functional group?

Answer 19

COOH

Question 20

Carboxylic acid and carbonate?

Answer 20

Co2+ Oate + water

Question 21

Uses of carboxylic acids?

Answer 21

Dissolved in water=vinegar

Citrix scud

Soaps and detergents

Prep of esters

Solvent for organic molecules

Question 22

What is hard water?

Answer 22

Contains ca 2+ or mg2+

Reacts with soap =scum

When boiled forms scale

Ca good for teeth
Less risk of heart disease

Question 23

What is the difference between temporary and permanent hardness?

Answer 23

Temporary = hydrogencarbonate ions

Permanent= calcium sulphate

Question 24

How to remove hardness?

Answer 24

Temporary - boiling

Either- exchange columns containing Na+ or H+

Question 25

Flame test for ``` Lithium Sodium Potassium Calcium Barium Ions ```

Answer 25

``` Crimson Yellow Lilac Red Green ```

Question 26

Test for chlorine!

Answer 26

Bleaches damp litmus paper (red to white)

Question 27

Test for oxygen?

Answer 27

Relighted a glowing splint

Question 28

Test for hydrogen

Answer 28

Squeaky pip with lighted splint

Question 29

Test for metal ions? ``` Results of Calcium Copper ii Iron ii Iron iii Aluminium Magnesium ```

Answer 29

NaOH ``` White Blue Green Brown White - redesolves in excess White ```

Question 30

Test for carbonates

Answer 30

Bubbling through lime water Goes cloudy

Question 31

Test for halides

Answer 31

Add nitric acid the silver nitrate Cl=white Br=cream I=yellow

Question 32

Test for sulphate?

Answer 32

AddHCl then BaCl2 White precipitate (bariumsulphate)

Question 33

What if metal ions and hydrogen ions present?

Answer 33

Metal ions stay in solution and hydrogen forms at negative electrode unless metal is less reactive

Question 34

If OH and halide ions are present?

Answer 34

Halide will form, if not there then oxygen will Positive electrode

Question 35

How to electroplate?

Answer 35

Negative electrode is the metal object that wants plating Positive electrode is pure metal you want it plated with Metal ions travel to negative electrode Metal ions leave positive electrode

Question 36

Electroplating silver?3

Answer 36

Silver nitrate

Question 37

Electroplating copper?

Answer 37

Copper sulphate

Question 38

How to separate insoluble solids?

Answer 38

Filtration and crystallisation

Question 39

Ionic compounds properties?

Answer 39

``` High melting point High boiling point Carry electric charge when molten Dissolve easily Carry electric current in solution ```

Question 40

Alkali metal properties?

Answer 40

Shiny when freshly cut but tarnish as they react with oxygen in moist air Reactivity increases Higher density Lower melting point Lower boiling point React with water to produce hydrogen gas and hydroxide metal Form ionic compounds with non metals

Question 41

Halogen properties

Answer 41

Decrease in reactivity Melting and boiling point increase Electronegativity decreases React with alkali metals to form salt Higher up displace lower in ionic

Question 42

Colours of halogens

Answer 42

Fluorine= yellow gas (poisonous and v reactive) Chlorine=dense green gas (fairly reactive and poisonous) Bromine=red/brown volatile liquid (dense and poisonous) Iodine=dark grey crystaline solid or purple vapour

Question 43

How to make bleach?

Answer 43

Mix sodium hydroxide with chlorine gas

Question 44

Properties of noble gases?

Answer 44

Inert Colourless gas Boiling point increases Density increases

Question 45

Uses of argon?

Answer 45

Inert atmosphere in filament lamps | Protect metals that are being welded Inert atmosphere prevents reacting with oxygen

Question 46

Uses of helium?

Answer 46

Airships and balloons Less dense than air so they float

Question 47

What is sand?

Answer 47

Silicon dioxide

Question 48

What is mass spectrometry used for?

Answer 48

To find the Mr A molecular ion is made when bombarded with electrons to remove one = highest mass furthest to the right

Question 49

Equation for % mass?

Answer 49

Ar x number of atoms/Mr of whole compound X100